Heading to Europe and wondering how you can avoid coming home to a wireless bill as big as your mortgage payment?

In this edition of Ask Maggie I offer some advice about using a smartphone abroad to a reader traveling to Spain next week for the Mobile World Congress trade show. Getting a local SIM card to pop into an unlocked GSM phone is likely the cheapest option. But if used carefully, subscribers don't have to sacrifice their kids' college funds to pay for a U.S. wireless plan with international roaming. Ask Maggie shows you how. Also in this Ask Maggie, I tell one man anxious to upgrade his iPhone 3GS to the iPhone 4S to hold on another few months to see what new iPhone Apple will announce in 2012.

Local prepaid SIM vs. international roaming dilemma

Dear Maggie,
I am heading to Mobile World Congress in Barcelona next week. I know you and the CNET crew have been to this show several times. Anyway, I need help figuring out what to do about using a phone while I am there. This is my first time going to MWC, and I want to know whether I should get a local SIM card for my iPhone, or if I should just use my existing wireless plan while I am away and hope for the best. I definitely don't want to come home to a $1,000 phone bill! What's my best option? Help!

Thanks,
MWC Virgin

Dear MWC Virgin
First of all, glad to hear you will be coming to Barcelona! Mobile World Congress is a terrific and exciting event. And Barcelona is one of the best cities in the world with amazing art and architecture and yummy food and wine. It's my favorite show of the year!

Attendees stroll the grounds of the Fira de Barcelona at the 2011 Mobile World Congress.
Kent German/CNET

Now to answer your question. Traveling internationally with a cell phone, and especially a smartphone, can be very expensive if you aren't careful. As you noted in your question, there are several stories of people coming home from a trip to find they've racked up hundreds or even thousands of dollars in roaming usage fees. Once you know how much carriers charge to roam onto a foreign carrier's network, you'll understand why. It's highway-robbery. For example, AT&T charges about $1.40 per minute for phone calls made while roaming in Spain. And it charges 50 cents per text message, and 1.95 cents per kilobyte of data. (Even though a couple of pennies per kilobyte may not sound like a lot, it adds up very quickly. This is kilobytes we are talking about here, not megabytes.)

Getting a foreign SIM card for your phone will be the least expensive option for you. But there are a couple of drawbacks. First, you have to take time out of your travels to go to a store to buy the SIM card. You'll also have to get a local Spanish phone number, which means that calls to your U.S. number won't ring on your phone, unless you are able to forward the calls. This means that you will have to give out your local Spanish number. And since these SIM cards and phone numbers only last for one year, it's unlikely you'll be able to reuse the same SIM and number when you return to MWC next year.

The way local prepaid SIM cards work is that instead of using your regular wireless service, you will pop out your existing SIM card and put in a new prepaid SIM card from a local Spanish carrier. The SIM card basically changes your service from your U.S. carrier to a Spanish carrier's network. This is why you will have a new local phone number in Spain.

The other thing to consider is that using a SIM card from a local carrier only works if you have an unlocked GSM "world" phone. Most phones from AT&T and T-Mobile USA fit this category. But if you have the iPhone and AT&T is your carrier, AT&T will not unlock the device for you to use it overseas. That said, you can get AT&T to unlock other smartphones for you. And T-Mobile also unlocks phones used on its network. Of course, this doesn't mean that an AT&T iPhone can't be unlocked. But AT&T won't help you do it, so you'll have to do it on your own.

If you are a Verizon Wireless or Sprint Nextel customer, you need to be sure that the phone you plan to use in Spain is a "world" phone. Verizon and Sprint use a technology called CDMA. But European carriers, including those in Spain, use GSM technology. To serve customers who want to take their phones abroad, Sprint and Verizon offer some "world" phones that have both CDMA and GSM radios in them. These phones can roam onto foreign carrier networks or they can be unlocked and a local SIM card can be used. Verizon and Sprint will unlock any "world" smartphone so long as the subscriber meets the individual carrier's requirements.

Back to your question. Should you get a local SIM instead of roaming using your existing U.S.-based wireless service? It really depends on how long you will be in Spain or any other country you're visiting on your trip. And it depends on whether you want to go through the hassle of buying a new SIM and using a Spanish number while you're away. If you plan on using a lot of data or you will be gone for more than a couple of weeks, the local SIM option might be a better choice. But there are also ways to use a U.S. roaming service without paying an arm and a leg.

I checked with a local Orange store in Barcelona and you can buy a SIM card for 5 euros ($6.72). With that card, you have to add a minimum of 10 euros ($13.47) onto the card, for a total of 15 euros ($20). If you want to use 3G data, you can access 100MB of data for seven days for 4.20 euros ($5.65.) If you exceed 100MB in that week, the service is slowed down. But you aren't charged an overage fee.This plan also includes 50 SMS messages per week, but it's restricted to messages sent to Spanish phones only. Incoming text messages are free. SMS text messages sent to a U.S. number will cost you 0.70 euros (94 cents) each.

When it comes to data, the local prepaid option is much more cost-effective. Under its international roaming plan, AT&T charges $50 for 125MB of data for the month and an outrageous $200 for 800MB of data. If you exceed that amount, AT&T charges $10 for an additional 10MB.

But for some people, myself included, getting a local SIM card for a short trip is a hassle. Also my iPhone service is with AT&T, and AT&T is the only U.S. carrier that does not unlock the iPhone for its subscribers. So if I want to use my phone and if I don't want to unlock it myself, I have to roam.

The best way to avoid outrageously expensive fees while abroad is to sign up for an international roaming plan with your carrier before you leave on your trip. Even though the plans are hefty in comparison to your regular monthly U.S. service and they are more expensive than the local SIM card option, they can help you significantly reduce the cost of using your device while abroad.

Here's a "smart" way to use your smartphone with your current U.S. service plan while in Spain.

Before you leave, call your carrier or go to the Web site and log into your account. Go to the section for International roaming plans. In AT&T's case, you can sign up for an international roaming service for $5.99 per month. This fee will not give you any free calling minutes, but it will reduce the per minute rate you will pay for calls. So instead of paying $1.40 per minute to call from Spain, it will cost you $1 per minute. While 40 cents may not sound like a lot, if you plan to be chatting a lot, those minutes add up quickly and the $5.99 you spend on international roaming for voice doesn't sound like a bad idea. To cut down on voice costs, use Skype or some other voice over IP app when you're in a Wi-Fi hot spot. This way you can keep your voice minutes to a minimum and keep costs down.

Next pick a messaging plan. AT&T offers several options here. You can get 50 messages for $10 a month, 200 messages for $30 a month, or 500 messages for $50. Check your history to see how many text messages you think you may need. Remember that these buckets of messages are for an entire month, but you will only be in Spain for one week. So consider how many messages you think you will send and receive in a week versus how many you might need monthly. If you go over your allotment it's between 10 cents and 20 cents per text. Keep in mind that if you get a prepaid SIM, the text messages that come with your plan are messages sent to Spanish numbers only. So if you're going to be texting people with U.S. cell phones, you'll be charged nearly a $1 per text.

One way to avoid text message fees is to bypass the SMS system by using Web-based messaging apps on your smartphone. Again, keep in mind, that these messaging apps use data, so it's not entirely free either.

As I mentioned before, international roaming for data is really expensive even when you buy a package from your U.S. carrier. This is where a prepaid option with a local carrier can be much more cost-effective. But if you are going to use a U.S. plan, use data judiciously. Keep in mind that when you use data while in a Wi-Fi mobile hot spot, you won't be eating up your allotted data from your carrier. In fact, I recommend making sure that the hotel you're staying in or the apartment you're renting has Wi-Fi for this purpose. Look at your data usage history to figure out which plan is the best fit for you. Remember you will only be in Spain for a week, so if you're a light user and you can leverage Wi-Fi as much as possible, you won't need the high-end plan. My advice is to go as low as you can in terms of a data package and use Wi-Fi wherever and whenever possible.

If you don't want to use data roaming at all or if you want to make sure you aren't unknowingly using data when you aren't near Wi-Fi, you can turn off international data roaming on your smartphone. And when you need it, you can turn it back on. That choice will live somewhere in your Settings menu (on the iPhone go to Settings > General > Network and deactivate "Cellular data" and "Data roaming").

By turning it off, you'll ensure that your phone won't be constantly downloading new e-mails or data for your apps (text messages and calls won't be affected). For the times when you're not near Wi-Fi, you can activate the setting, download what you need, and turn it off again. Another thing you can do is to turn off all push-notifications and automatic e-mail downloads.

If you can use Wi-Fi and you are careful about your usage, you should be fine signing up for a minimal package. For example, I signed up for the $6 international voice roaming service, $30 for 200 text messages, and $25 for 50MB of data. All told, I'm adding $61 to my monthly bill.

One thing to keep in mind is that even though you only need the international roaming service for a week, you must keep the service until the end of your billing cycle. If you cancel the services before the end of the billing cycle, the cost will be prorated. This also means that the usage will be prorated. So if you signed up for 50MB of data, you won't get the full 50MB. You will mostly likely only get a quarter of that total.

The other thing to remember is that you must cancel the service at the end of the billing cycle, or you will continue to get charged for the international roaming plans month after month. AT&T has a handy tool on its Web site that allows you to pick the activation and termination dates of the services when you change them in your account. And it marks the date when your billing cycle starts and ends to help you figure out when you should terminate service.

I hope this advice was helpful. Have a great time in Barcelona! And if you see me wandering around the Fira or dashing into a keynote, be sure to say "hi!"

Upgrade to the iPhone 4S now or wait for the iPhone 5?

Dear Maggie,
I have a dilemma and I need your expert advice. A couple of weeks ago I dropped my iPhone 3GS. And yes, I did cry a little (don't judge me!). Now it has a small crack on the top right corner. The phone works great, the crack doesn't interfere with the performance of the phone. But I still want a new iPhone. Should I use my upgrade and buy the iPhone 4S or should I wait and see what the iPhone 5 is all about? If I wait for the iPhone 5 my 3GS with the cracked screen will be worth even less than it is now. If I get the 4S what happens come June if the iPhone5 is the most amazing iPhone yet??? Should I buy the 4S and when the 5 comes out use my wife's upgrade to get the 5 and give her the 4S and be THAT guy?

Please help,
All Cracked Up

Dear All Cracked Up,
Please don't be that guy. Be patient and wait for the iPhone 5 to come out. Most likely, you'll only have to wait until June or July. It's already nearly March, so that isn't too far off. Worst case scenario, you wait until September or October. If your iPhone 3GS is still holding up even after you dropped it, count your blessings.

Apple

I have a 3GS with an ailing battery. If I use the browser or too many Web-enabled apps in a row, the phone just poops out without warning, crashing into the black screen of death until I hook it up to a charger to bring it back to life. Believe me, I really want a new phone, too. I need a new phone. But I am waiting for Apple's new iPhone, because it just doesn't make sense to buy the iPhone 4S now when I am fairly certain that within the next few months a newer and better model will probably be available.

Now, don't get me wrong. The iPhone 4S is a great phone. In fact, it's Apple's hottest selling iPhone to date. And there are still plenty of people buying these smartphones. But when you know a newer model is right around the corner and you don't really "need" a new device, I think it's better to wait.

I wouldn't worry too much about the resale value of your iPhone 3GS. It's not worth that much now. And the amount it depreciates between now and when the iPhone 5 goes on sale is nowhere near the difference between buying a new iPhone at the subsidized price versus buying it at the unsubsidized price.

As for stealing your wife's upgrade so you can get the instant gratification of the iPhone 4S today and the delight of the iPhone 5 later, I beg you not to be that guy. Your wife deserves to get the latest and greatest iPhone, too. It's not fair for you to satisfy your need for a new toy, and leave your wife with your cast-offs. And please tell me this way of thinking isn't something I have to look forward to after I get married in September! Ha! I may stay on my own separate wireless plan after all if this is how most husbands think!

Good luck with the big decision. I hope my advice was helpful! And if you do steal your wife's upgrade, so you can get the iPhone 4S now and the iPhone 5 later, make sure you make it up to her with some really nice jewelry.

Ask Maggie is an advice column that answers readers' wireless and broadband questions. The column now appears twice a week on CNET offering readers a double dosage of Ask Maggie's advice. If you have a question, I'd love to hear from you. Please send me an e-mail at maggie dot reardon at cbs dot com. And please put "Ask Maggie" in the subject header. You can also follow me on Facebook on my Ask Maggie page.

About the author

Marguerite Reardon has been a CNET News reporter since 2004, covering cell phone services, broadband, citywide Wi-Fi, the Net neutrality debate, as well as the ongoing consolidation of the phone companies. E-mail Maggie.
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